Esters of conjugated unsaturated acids (conjugated acid esters), corresponding methods and use

ABSTRACT

Esters (A) of conjugatedly unsaturated carboxylic acids process for preparing them, and compositions containing said esters, curable with actinic radiation, curable thermally and with actinic radiation or curable oxidatively.

The present invention relates to novel esters of conjugatedlyunsaturated acids (conjuenic acid esters), in particular to novel estersof conjugatedly unsaturated fatty acids (conjuenic fatty acid esters).

The present invention also relates to a novel process for preparingconjuenic acid esters, especially conjuenic fatty acid esters.

The present invention further relates to the use of the novel conjuenicacid esters, especially the conjuenic fatty acid esters, as or toprepare compositions curable with actinic radiation.

The present invention relates not least to the use of the novelcompositions curable with actinic radiation as coating materials,adhesives and sealants for producing coatings, paint systems, primers,adhesive films, and seals, and also for producing moldings andself-supporting films.

The enzymatic esterification of itaconic acid with fatty acids, such aslauric acid, phenylundecanoic acid and undeceneoic acid, is known fromthe dissertation entitled “Synthesen und Untersuchungen zumPolymerisationsverhalten von Itaconsäurederivaten” [Syntheses andinvestigations of the polymerization characteristics of itaconic acidderivatives] by Christine Rüdiger, Department of Natural Sciences II,University of Wuppertal, 1998. The use of the esters as or to preparecompositions which are curable with actinic radiation or both thermallyand with actinic radiation or which are air-drying (oxidatively curable)is not described.

For curing with actinic radiation, especially with UV radiation,preference is given to the use of what are termed 100% systems ascompositions curable with actinic radiation which are substantially orentirely free from organic solvents and whose ingredients are all, orvirtually all, incorporated into the three-dimensional network of thecured compositions which forms as they cure, so that there is no need toincinerate volatile organic compounds. These 100% systems therefore alsoconform to the strict VOC (volatile organic content) guidelines, whosepurpose is avoid the emission of volatile organic compounds, especiallysolvents.

Despite these substantial advantages, the 100% systems which can becured with actinic radiation also have certain disadvantages. Forinstance, their viscosity is frequently too high for the majority ofapplication methods, particularly spray application or rollerapplication. As is known, the viscosity can be lowered by using reactivediluents, such as isobornyl acrylate (cf. also Römpp Online, 2002,“reactive diluents”) or 2-ethylhexyl acrylate (cf. also Römpp Online,2002, “2-ethylhexyl acrylate”). These reactive diluents are able to givethe cured compositions good properties, such as good adhesion and alsohigh water resistance and scratch resistance. At the same time, however,they increase the brittleness of the cured compositions. Since thereactive diluents, on curing, form a particularly close-meshedthree-dimensional network, they also lead to an unwanted contraction onpolymerization. Numerous known reactive diluents, not least, have a veryintense, unpleasant odor to them, leading to a severe odor nuisanceaccompanying the preparation and application of the correspondingcompositions that are curable with actinic radiation.

It is an object of the present invention, therefore, to provide novel,olefinically unsaturated monomers, particularly novel conjuenic acidesters, especially novel conjuenic fatty acid esters, which no longerhave the disadvantages of the prior art but which instead effectivelylower the viscosity of 100% system so that they are easily applied bythe conventional methods.

The novel conjuenic acid esters, especially the conjuenic fatty acidesters, ought to be preparable easily, safely and reproducibly, avoidingthe known disadvantages of the thermal processes for preparingolefinically unsaturated esters, such as time-consuming syntheses withthe high risk of polymerization as a secondary reaction.

The novel compositions curable with actinic radiation, particularly thenovel 100% systems, that are prepared with the aid of the novelconjuenic acid esters, particularly of the novel conjuenic fatty acidesters, ought to be able to be cured not only with actinic radiation butalso thermally and/or oxidatively. The cure should be rapid and shouldnot accompanied by a disruptive contraction on polymerization.

The resultant novel cured compositions ought to exhibit excellentadhesion to the conventional substrates, excellent water resistance,excellent scratch resistance, and a high anticorrosion effect. Theyought not to tend toward embrittlement.

The invention accordingly provides the novel esters (A) of conjugatedlyunsaturated carboxylic acids (conjuenic acid esters) of the generalformula I:X_(m)Y_(n)   (I),in which the indices m and n stand for 1 or an integer >1 and thevariables X and Y are defined as follows:

-   -   X is a radical derived from an olefinically unsaturated        carboxylic acid containing one or more than one carboxyl group,        6 to 60 carbon atoms and at least two conjugated double bonds in        the molecule (conjuenic acid); and    -   Y is a monovalent or polyvalent organic radical containing at        least one bond which can be activated with actinic radiation;        with the provisos that    -   (1) m=1 and Y=monovalent radical if X is derived from a        conjuenic acid having more than one carboxyl group in the        molecule, and    -   (2) n=1 and X=derived from a conjuenic acid having one carboxyl        group in the molecule if Y=polyvalent radical.

The novel esters (A) of conjugatedly unsaturated carboxylic acids arereferred to below as “conjuenic acid esters (A) of the invention”.

The invention also provides the novel process for preparing esters ofconjugatedly unsaturated carboxylic acids (conjuenic acid esters) byreacting

-   -   (i) at least one olefinically unsaturated carboxylic acid        containing one or more than one carboxyl group, 6 to 60 carbon        atoms and at least two conjugated double bonds in the molecule        (conjuenic acid) or at least one ester of said conjuenic acid        with    -   (ii) at least one hydroxyl-containing compound containing at        least one bond which can be activated with actinic radiation in        the presence of a catalyst, which involves using as catalyst at        least one enzyme which catalyzes the transesterification or        esterification and/or at least one organism which catalyzes the        transesterification or esterification, said process being        referred to below as “process of the invention”.

Further subject matter of the invention will emerge from thedescription.

In the light of the prior art it was surprising and unforeseeable forthe skilled worker that the object on which the present invention wasbased could be achieved by means of the conjuenic acid esters (A) of theinvention and by means of the process of the invention.

In particular it was surprising that by virtue of the conjuenic acidesters (A) of the invention it was possible effectively to lower theviscosity of 100% systems curable with actinic radiation, so that theycould be applied readily using the conventional methods.

The conjuenic acid esters (A) of the invention were prepared simply,safely and reproducibly without the known disadvantages of the thermalmethods of preparing olefinically unsaturated esters, such astime-consuming syntheses with the high risk of polymerization as asecondary reaction.

The curable compositions of the invention, especially the 100% systemsof the invention, that were prepared with the aid of the conjuenic acidesters (A) of the invention were curable not only with actinic radiationbut also thermally and/or oxidatively. The cure was rapid and was notaccompanied by a disruptive contraction on polymerization. Moreover,there was little or no odor nuisance during the preparation, applicationor curing of the curable compositions of the invention.

The resultant cured compositions of the invention adhered outstandinglyto the conventional substrates and had an excellent water resistance, ahigh anticorrosion effect, and an excellent scratch resistance.Surprisingly, they showed no tendency toward embrittlement.

The conjuenic acid esters (A) of the invention have the general formulaI.

In the general formula I the indices m and n stand for 1 or aninteger >1, preferably 1, 2, 3 or 4, more preferably 1, 2 or 3, verypreferably 1 or 2, especially 1, with the provisos that

-   -   (1) m=1 and Y=monovalent radical, as described below, if X, as        described below, is derived from a conjuenic acid having more        than one carboxyl group, preferably two, three or four, more        preferably two or three and especially two carboxyl groups in        the molecule, and    -   (2) n=1 and X=derived from a conjuenic acid having one carboxyl        group in the molecule if Y=polyvalent, preferably di-, tri- or        tetravalent, more preferably divalent or trivalent and        especially divalent radical.

The variable X stands for a radical derived from a carboxylic acidcontaining conjugated olefinic unsaturation, or conjuenic acid,containing one carboxyl group or more than one carboxyl group,preferably two, three or four, more preferably two or three andespecially two carboxyl groups, 6 to 60, preferably 6 to 40 andespecially 6 to 30 carbon atoms, and at least two and in particular fromtwo to six, conjugated double bonds in the molecule. In particular theradical X is derived from a conjuenic acid containing one carboxylgroup.

The variable X preferably stands for a radical which is derived from afatty acid containing conjugated olefinic unsaturation, or conjuenicfatty acid.

The conjuenic fatty acids and their esters, described below, areprepared preferably from olefinically unsaturated fatty acids, such aslinoleic acid, linolenic acid or arachidonic acid, whose isolated doublebonds are converted into conjugated double bonds under the action ofalkali or by a biotechnological method.

The conjuenic fatty acids are conventional products and are sold, forexample, under the brand name Isomerginsaure® SF, SY or SK by HarburgerFettchemie or under the brand name Edenor® UKD 6010, 5010 and 5020 byCognis.

In the general formula I the variable Y stands for a monovalent orpolyvalent, preferably di-, tri- or tetravalent, more preferably di- ortrivalent and especially divalent radical, but in particular amonovalent organic radical, which contains at least one, especially one,bond which can be activated with actinic radiation. In the context ofthe present invention actinic radiation means electromagnetic radiation,such as near infrared (NIR) visible light, UV radiation, X-rays andgamma radiation, especially UV radiation, and corpuscular radiation,such as electron beams, proton beams, alpha radiation, beta radiation,and neutron beams, especially electron beams.

The bond which can be activated with actinic radiation becomes reactivewhen exposed to actinic radiation and, together with other activatedbonds of its kind, enters into addition polymerization reactions and/orcrosslinking reactions which proceed in accordance with free-radicaland/or ionic mechanisms. Examples of suitable bonds are carbon-hydrogensingle bonds or carbon-carbon, carbon-oxygen, carbon-nitrogen,carbon-phosphorus or carbon-silicon single bonds or double bonds, orcarbon-carbon triple bonds. Of these, the carbon-carbon double bonds andtriple bonds are advantageous and are therefore used with preference inaccordance with the invention. The carbon-carbon double bonds areespecially advantageous, and so are used with particular preference. Forthe sake of brevity they are referred to below as “double bonds”.

The radical Y is preferably selected from the monovalent radicals of thegeneral formula III:

in which the variables are defined as follows:

-   -   R is a bonding electron pair between the olefinic carbon atom        and the oxygen atom of the oxycarbonyl group of the conjuenic        acid radical or organic radical linking to the oxycarbonyl group        of the conjuenic acid radical; and    -   R¹, R²    -   and R³ independently of one another are each a hydrogen atom or        organic radical, it being possible for at least two of the        radicals R, R¹, R², and R³ to be cyclically linked to one        another;        and from the polyvalent, preferably di-, tri- and tetravalent,        more preferably di- and trivalent and especially divalent        radicals of the general formula IV:        in which the variables are defined as follows:    -   R⁴,R⁵,    -   R⁶ and R⁷ independently of one another are each a bonding        electron pair between the olefinic carbon atom and the oxygen        atom of the oxycarbonyl group of the conjuenic acid radical or        organic radical linking to the oxycarbonyl group of the        conjuenic acid radical, with the proviso that a radical R⁴, R⁵,        R⁶ or R⁷ which has no linking function is a hydrogen atom or an        organic radical, preferably a hydrogen atom, it being possible        for at least two of the organic radicals R⁴, R⁵, R⁶ or R⁷ to be        linked cyclically to one another.

The linking organic radical R is preferably selected from the groupconsisting of aliphatic, cycloaliphatic, aromatic,aliphatic-cycloaliphatic, aliphatic-aromatic, cycloaliphatic-aromaticand aliphatic-cycloaliphatic-aromatic radicals which may contain atleast one ether, thioether, carboxylate, thiocarboxylate, carbonate,thiocarbonate, phosphate, thiophosphate, phosphonate, thiophosphonate,phosphite, thiophosphite, sulfonate, amide, amine, thioamide,phosphoramide, thiophosphoramide, phosphonamide, thiophosphonamide,sulfonamide, imide, hydrazide, urethane, urea, thiourea, carbonyl,thiocarbonyl, sulfone and/or sulfoxide group.

The linking organic radical R preferably contains at least onecarboxylate and/or amide group. With particular preference the divalentorganic radical R is composed of a carboxylate group and an alkylene,cycloalkylene and/or arylene group or of an amide group and an alkylene,cycloalkylene and/or arylene group.

Highly suitable alkylene groups R contain one carbon atom or 2 to 6carbon atoms. Highly suitable cycloalkylene groups R contain 4 to 10,especially 6, carbon atoms. Highly suitable arylene groups R contain 6to 10, especially 6, carbon atoms.

The variable R stands in particular for a linking organic radical Rcomposed of a carboxylate group and at least one, especially one,alkylene, cycloalkylene and/or arylene group, particularly an alkylenegroup, (—C(O)—O-alkylene-). With particular preference the variable Rstands for the radicals—C(O)—O—CH₂—,—C(O)—O—(—CH₂—)₂—,—C(O)—O—(—CH₂—)₃— and—C(O)—O—(—CH₂—)₄—.

Examples of suitable organic radicals R¹, R² and R³ include or consistof alkyl, cycloalkyl, and/or aryl groups. Highly suitable alkyl groupscontain one carbon atom or 2 to 6 carbon atoms. Highly suitablecycloalkyl groups contain 4 to 10, especially 6, carbon atoms. Highlysuitable aryl groups contain 6 to 10, especially 6, carbon atoms.

The organic radicals R, R¹, R² and R³ can be substituted orunsubstituted. However, the substituents must not disrupt the conduct ofthe process of the invention and/or inhibit the activation of the groupswith actinic radiation. Preferably the organic radicals R, R¹, R² and R³are unsubstituted.

Examples of especially suitable radicals Y of the general formula IIIare

-   -   2-(vinylcarbonyloxy)-,    -   2-(1-methylvinylcarbonyloxy)-,    -   2-(1-ethylvinylcarbonyloxy)-,    -   2-(propenylcarbonyloxy)-,    -   2-(styrylcarbonyloxy)-,    -   2-(cyclohexenylcarbonyloxy)-,    -   2-(endomethylenecyclohexylcarbonyloxy)-,    -   2-(norbornenylcarbonyloxy)- and    -   2-(dicyclopentadienylcarbonyloxy)eth-1-yl groups,    -   3-(1-methylvinylcarbonyloxy)-,    -   3-(1-ethylvinylcarbonyloxy)-,    -   3-(propenylcarbonyloxy)-,    -   3-(styrylcarbonyloxy)-,    -   3-(cyclohexenylcarbonyloxy)-,    -   3-(endomethylenecyclohexylcarbonyloxy)-,    -   3-(norbornenylcarbonyloxy)- and    -   3-(dicyclopentadienylcarbonyloxy)prop-1-yl groups, and    -   4-(vinylcarbonyloxy)-,    -   4-(1-methylvinylcarbonyloxy)-,    -   4-(1-ethylvinylcarbonyloxy)-,    -   4-(propenylcarbonyloxy)-,    -   4-(styrylcarbonyloxy)-,    -   4-(cyclohexenylcarbonyloxy)-,    -   4-(endomethylenecyclohexylcarbonyloxy)-,    -   4-(norbornenylcarbonyloxy)- and    -   4-(dicyclopentadienylcarbonyloxy)but-1-yl groups, especially    -   4-(vinylcarbonyloxy)but-1-yl groups.

The linking organic radicals R⁴, R⁵, R⁶ and/or R⁷ are preferablyselected from the group consisting of the above-described linkingorganic radicals R. Particularly advantageous linking organic radicalsR⁴, R⁵, R⁶ and/or R⁷ are composed of a carboxylate group and at leastone, especially one or two, alkylene, cycloalkylene, and/or arylenegroups, in particular one or two alkylene groups, (—C(O)—O-alkylene- or-alkylene-C(O)—O-alkylene-). Especially preferred linking organicradicals R⁴, R⁵, R⁶ and/or R⁷ are—C(O)—O—CH₂—,—C(O)—O—(—CH₂—)₂—,—C(O)—O—(—CH₂—)₃—,—C(O)—O—(—CH₂—)₄—,—CH₂—C(O)—O—CH₂—,—CH₂—C(O)—O—(—CH₂—)₂—,—CH₂—C(O)—O—(—CH₂—)₃—, and—CH₂—C(O)—O—(—CH₂—)₄—.

The nonlinking organic radicals R⁴, R⁵, R⁶ and/or R⁷ are preferablyselected from the group consisting of the above-described organicradicals R¹, R² and R³.

Examples of especially suitable radicals Y of the general formula IV are—CH₂—O—(O)C—CH═CH—C(O)—O—CH₂—,—(—CH₂—)₂—O—(O)C—CH═CH—C(O)—O—(—CH₂—)₂—,—(—CH₂—)₃—O—(O)C—CH═CH—C(O)—O—(—CH₂—)₃— and—(—CH₂—)₄—O—(O)C—CH═CFH—C(O)—O—(—CH₂—)₄—in the cis and trans forms and also

The conjuenic acid esters (A) of the invention may include at least oneconjuenic acid ester (B) of the general formula II:X_(m)Z   (II),in which the index m stands for 1 or an integer >1, in particular for 1or 2, especially 2, the variable X is as defined above, and the variableZ stands for a saturated or aromatic, preferably saturated, especiallyalicyclically saturated, organic radical having a valence of 1 or >1,preferably of 1 or 2, in particular of 2.

Examples of especially suitable monovalent radicals Z are 4-hydroxy-,3-hydroxy- and 2-hydroxy-cyclohexane and -benzene and alsoomega-hydroxyalkyl radicals having 1 to 10, preferably 2 to 4, carbonatoms, especially 2-hydroxyethyl, 3-hydroxypropyl and 4-hydroxybutylradicals.

Examples of especially suitable divalent radicals Z arecyclohexane-1,4-, -1,3- and -1,2-diyl, 1,4-, 1,3- and 1,2-phenylene, andalkylene radicals having 1 to 10, preferably 2 to 4, carbon atoms,especially eth-1,2-ylene, prop-1,3-ylene (trimethylene) andbut-1,4-ylene(tetramethylene).

The inventive mixture of conjuenic acid ester (A) of the invention andconjuenic acid ester (B) may contain up to 50% by weight of conjuenicacid ester (B).

The conjuenic acid esters (A) of the invention and the inventive mixtureof conjuenic acid ester (A) of the invention and conjuenic acid ester(B) may be prepared basically in accordance with the conventionalmethods of preparative organic chemistry for the preparation of esters.It is of advantage, however, to prepare them by the process of theinvention.

The process of the invention involves reacting

-   -   (i) at least one of the above-described conjuenic acids,        especially conjuenic fatty acids, or at least one ester of these        conjuenic acids, especially conjuenic fatty acids, preferably at        least one cycloalkyl, alkyl or aryl ester, preferably an alkyl        ester, in particular an ester of a low molecular mass alcohol        having 1 to 10, preferably 1 to 4, carbon atoms, especially        methanol, ethanol, propanol, isopropanol, n-butanol or        isobutanol, or of a polyol, especially ethylene glycol,        propylene glycol, neopentyl glycol, glycerol,        trimethylolpropane, penta-erythritol or a sugar alcohol such as        sorbitol or mannitol,    -   (ii) with at least one, especially one, hydroxyl-containing        compound containing at least one, especially one, of the        above-described bonds which can be activated with actinic        radiation, in the presence of a catalyst.

In accordance with the invention the catalyst used is at least one,especially one, enzyme which catalyzes the transesterification oresterification and/or at least one, especially one, organism whichcatalyzes the transesterification or esterification.

Enzymes used are hydrolases [EC 3.x.x.x], especially esterases [EC3.1.x.x] and proteases [EC 3.4.x.x]. Preference is given to the carboxylester hydrolases [EC 3.1.1.x]. Particular preference is given to usinglipases as hydrolases. Use is made in particular of lipases fromAchromobacter sp., Aspergillus sp., Burkholderia sp., Candida sp., Mucorsp., Penicillium sp., Pseudomonas sp., Rhizopus sp., Thermomyces sp. orporcine pancreas. The enzymes and their functions are described in, forexample, Römpp Online 2002, “hydrolases”, “lipases” and “proteases”.They may be mobilized or immobilized.

Suitable organisms include all naturally occurring or geneticallymodified microorganisms, single-celled life forms or cells whichcatalyze the transesterification or esterification by means of ahydrolase [EC 3.x.x.x], preferably an esterase [EC 3.1.x.x] or protease[EC 3.4.x.x], with particular preference a carboxyl ester hydrolase [EC3.1.1.x] and in particular a lipase. It is possible to use all theorganisms known to the skilled worker which contain hydrolases. It ispreferred to use organisms comprising lipases as hydrolases. Use is madein particular of Achromobacter sp., Aspergillus sp., Burkholderia sp.,Candida sp., Mucor sp., Penicillium sp., Pseudomonas sp., Rhizopus sp.,Thermomyces sp. and cells from porcine pancreas. The organisms inquestion may be the unaltered organisms themselves or geneticallymodified organisms which originally do not express the enzymes, or notto a sufficient extent, and which exhibit a sufficiently high enzymeactivity and productivity only following modification. Additionally, theorganisms may be adapted by means of genetic modification to thereaction conditions and/or culturing conditions.

The amount of enzyme and/or organism used may vary widely and is guidedby the requirements of the case in hand, in particular by the reactivityof the starting products and by the catalytic activity and selectivityof the enzyme or organism, and by the conditions chosen.

The enzyme is used preferably in an amount of from 0.1 to 20%, morepreferably from 0.2 to 16%, with particular preference from 0.2 to 14%,with very particular preference from 0.3 to 12% and in particular from0.5 to 10% by weight, based in each case on the total amount of thestarting products.

In the process of the invention it is possible to use any of a widevariety of hydroxyl-containing compounds. What is essential is thatduring the reaction they provide the above-described radicals Y,especially the radicals Y of the general formulae II or IV. Thehydroxyl-containing compounds are preferably selected from the groupconsisting of carboxylates and carboxamides of the general formulae V toX, more preferably V, VIII, IX and X and especially V:

in which the variables R, R¹, R², R³, R⁴, R⁵, R⁶ and R⁷ are as definedabove and the variable Q stands for an oxygen atom or a primary orsecondary imino group, preferably for an oxygen atom, and the variableR⁸ stands for a hydroxyl-containing monovalent organic radical. Themonovalent organic radical R⁸ preferably contains at least one,especially, one, primary and/or secondary, especially primary, hydroxylgroup. It also contains at least one, especially one, alkyl, cycloalkyland/or aryl group, in particular an alkyl group.

The hydroxyl-containing compounds are preferably selected from the groupconsisting of hydroxyl-containing esters and amides of acrylic acid,methacrylic acid, ethacrylic acid, crotonic acid, cinnamic acid,cyclohexenecarboxylic acid, endomethylenecyclohexanecarboxylic acid,norbornene-carboxylic acid, dicyclopentadienecarboxylic acid, fumaricacid, maleic acid, itaconic acid, endomethylenetetrahydrophthalic acidand methylendomethylenetetrahydrophthalic acid, preferably of acrylicacid, fumaric acid, maleic acid and itaconic acid, in particular ofacrylic acid.

Examples of especially suitable hydroxyl-containing compounds areN-methylolacrylamide, 2-hydroxyethyl acrylate, 3-hydroxypropyl acrylateand 4-hydroxybutyl acrylate, especially 4-hydroxybutyl acrylate.

In the process of the invention the molar ratio of conjuenic acid and/orconjuenic acid ester to hydroxyl-containing compound may vary widely.The molar ratio of conjuenic acid and/or conjuenic acid ester tohydroxyl-containing compound is preferably set so as to result in anequivalents ratio of carboxylic acid and/or carboxylate groups tohydroxyl groups of from 0.5:1.0 to 1.0:0.5, more preferably from0.65:1.0 to 1.0:0.65 and in particular from 0.8:1.0 to 1.0:0.8.

The reactions according to the process of the invention can be carriedout in a single-phase or multiphase, aqueous and/or organic reactionmedium. The starting products may be present in solution, suspension oremulsion. The reactions can be conducted with or without the addition ofsolvent. It is preferred to use solvents which are inert with regard tothe reactions. Particular preference is given to using conventionalorganic solvents, especially aprotic nonpolar solvents. It is alsopossible to use an excess of conjuenic acids and/or conjuenic acidesters or an excess of hydroxyl-containing compounds as the reactionmedium. With particular preference the reactions are conducted in bulk,in other words in the absence or the presence of small amounts oforganic solvents.

The process of the invention can be conducted at different temperatures.The selection of the temperature range is guided by the requirements ofthe case in hand, in particular by the reactivity of the startingproducts and their thermal stability and also by the catalytic activityand selectivity of the enzyme and/or organism and their thermalstability. The process of the invention is preferably conducted attemperatures from 0 to 100° C., more preferably from 10 to 80° C., withparticular preference from 15 to 75° C., and in particular from 20 to70° C.

The duration of the reactions may also vary widely and is likewiseguided by the requirements of the case in hand, in particular by thereactivity of the starting products and by the catalytic activity andselectivity of the enzyme and/or organism. The duration is preferablyfrom one hour to one week, more preferably from two hours to five days,with particular preference from three hours to four days, and inparticular from four hours to three days.

The process of the invention can be operated in batch mode, in whichcase all of the starting products are charged to a suitable reactionvessel, or in semibatch mode, in which case some or all of the startingproducts are metered into the reaction medium during the reaction.

The reactions in accordance with the process of the invention areaccompanied by the formation of water or of at least one, especiallyone, saturated hydroxyl-containing compound, for example methanol,ethanol, propanol or butanol. It is advisable to remove thehydroxyl-containing compound or the water from the reaction mixtureswhile it is being formed or immediately after it has formed. This can bedone employing any conventional method, such as vacuum distillation orazeotropic distillation, pervaporation or passage of inert gases, forexample. It is important here that the starting products, the catalysts,and the end products are not damaged thermally. It is also possible toadd substances to the reaction mixtures that absorb saturatedhydroxyl-containing compounds and/or water. These substances, however,must not disrupt the process of the invention—for example, by loweringthe catalytic activity of the enzyme and/or microorganism and/or bydeveloping their own catalytic activity. Examples of suitable absorbentsare molecular sieves of appropriate pore size (cf. also Römpp Online,2002, “molecular sieves” and “zeolites”).

The resultant conjuenic esters (A) of the invention and/or the inventivemixtures of the conjuenic acid esters (A) of the invention and theconjuenic acid esters (B) have numerous special advantages. Forinstance, they can be crosslinked or cured with just a low dose ofactinic radiation, especially UV radiation or electron beams. Further,they can be dried oxidatively, i.e. crosslinked or cured. They are lowin odor and do not tend to crystallize out or to form wax. Furthermore,they are highly compatible with all constituents of conventionalcompositions curable with actinic radiation, oxidatively and/orthermally. In the cured state they have excellent adhesion to metalsurfaces.

They can therefore be put to any of a wide variety of end uses. To suchends they can be isolated as substances from the reaction mixtures orused directly in solution. They are preferably used as novelcompositions curable with actinic radiation, both thermally and withactinic radiation (dual cure) or oxidatively, or in the function ofreactive diluents and/or adhesion promoters for preparing suchcompositions. The novel compositions curable with actinic radiation,both thermally and with actinic radiation (dual cure) or oxidatively arereferred to below as “compositions of the invention”.

The compositions of the invention accordingly contain up to 100% byweight of the conjuenic acid esters (A) of the invention and/or of theinventive mixture of at least one conjuenic acid ester (A) of theinvention and at least one conjuenic acid ester (B). The amount inquestion is preferably from 0.5 to 80%, more preferably from 1 to 60%,with particular preference from 1.5 to 50% and in particular from 2 to40% by weight, based in each case on the composition of the invention.

The compositions of the invention may comprise any conventionalconstituents of compositions curable with actinic radiation, oxidativelyand/or thermally, such as radiation-curable and thermally curablebinders, additional radiation-curable and thermally curable reactivediluents, other than the conjuenic acid esters (A) of the invention,thermally curable reactive diluents, and photoinitiators. They mayfurther include conventional auxiliaries and additives, such ascatalysts, plasticizers, light stabilizers, adhesion promoters(tackifiers), slip additives, leveling agents, polymerizationinhibitors, flatting agents, nanoparticles, and film-formingauxiliaries.

Examples of suitable conventional constituents of compositions curablewith actinic radiation are known for example from the German patent DE197 09 467 C1, page 4 line 30 to page 6 line 30, or the German patentapplication DE 199 47 523 A1.

If the composition of the invention is curable thermally as well, i.e.is a dual-cure composition, it preferably further includes conventionalthermosetting binders and crosslinking agents, which may also containgroups which can be activated with actinic radiation, and/orthermosetting reactive diluents, as is described in, for example, theGerman patent applications DE 198 18 735 A1 and DE 199 20 799 A1 or theEuropean patent application EP 0 928 800 A1.

The compositions of the invention are preferably prepared by mixing theabove-described constituents in suitable mixing units such as stirredtanks, stirrer mills, extruders, compounders, Ultraturrax devices,inline dissolvers, static mixers, micromixers, toothed-wheel dispersers,pressure release nozzles and/or microfluidizers. It is preferred here tooperate in the absence of light with a wavelength λ<550 nm or incomplete absence of light, in order to prevent premature crosslinking ofthe compositions of the invention.

The compositions of the invention may be present in any of a widevariety of forms. Thus, they are conventional compositions containingorganic solvents, aqueous compositions, substantially or completelysolvent-free and water-free liquid compositions (100% systems),substantially or completely solvent-free and water-free solid powders,or substantially or completely solvent-free powder suspensions (powderslurries). Moreover, they may be one-component systems, in which thebinders and the crosslinking agents are present alongside one another,or two-component or multicomponent systems, in which the binders and thecrosslinking agents are separate from one another until shortly beforeapplication. In particular they are 100% systems.

The compositions of the invention are used for producing compositionscured with actinic radiation, dual-cure compositions and oxidativelycured compositions, preferably coatings, primers, adhesive films, seals,moldings, and self-supporting films, especially primers.

To produce the moldings and films of the invention, the compositions ofthe invention are applied to conventional temporary or permanentsubstrates. For producing the films and moldings of the invention it ispreferred to use conventional temporary substrates, such as metal belts,plastic belts or hollow bodies made of metal, glass, plastic, wood orceramic, which can be easily removed without damaging the films andmoldings of the invention.

Where the compositions of the invention are used for producing coatings,adhesive films, primers and seals, permanent substrates are employed,such as means of transport, including aircraft, watercraft, railvehicles, muscle-powered vehicles and motor vehicles, and parts thereof,the interior and exterior of buildings and parts thereof, doors,windows, furniture, hollow glassware, coils, freight containers,packaging, small industrial parts, mechanical components, and componentsfor white goods. The films and moldings of the invention may likewiseserve as substrates.

In terms of method, the application of the liquid compositions of theinvention has no special features but can instead take place by anyconventional application method, such as spraying, squirting, knifecoating, brushing, flow coating, dipping, trickling or rolling, forexample.

The application of the compositions of the invention in powder form alsohas no particular features as far as its method is concerned but insteadtakes place, for example, by the conventional fluid-bed techniques, suchas are known, for example, from the BASF Coatings AG brochures“Pulverlacke für industrielle Anwendungen”, January 2000, or “CoatingsPartner, Pulverlack Spezial”, 1/2000, or Römpp Lexikon Lacke undDruckfarben, Georg Thieme Verlag, Stuttgart, New York, 1998, pages 187and 188, “electrostatic powder spraying”, “electrostatic spraying”, and“electrostatic fluidized-bath process”.

During application it is advisable to operate in the absence of actinicradiation in order to prevent premature crosslinking of the compositionsof the invention.

The applied compositions of the invention are preferably cured using UVradiation. During irradiation it is preferred to use a radiation dose offrom 100 to 6 000, more preferably from 200 to 3 000, more preferablystill from 300 to 2 000, and with particular preference from 500 to 1800 mJ cm⁻², the region <1 700 mJ cm⁻² being especially preferred.

The intensity of radiation may vary widely. It is guided in particularby the radiation dose on the one hand and the irradiation time on theother. For a given radiation dose, the irradiation time is guided by thebelt speed or rate of advance of the substrates in the irradiation unit,and vice versa.

As radiation sources for UV radiation it is possible to use allconventional UV lamps. Flash lamps are also suitable. As UV lamps it ispreferred to use mercury vapor lamps, more preferably low, medium andhigh pressure mercury vapor lamps, especially medium pressure mercuryvapor lamps. Particular preference is given to using unmodified mercuryvapor lamps plus appropriate filters or modified, especially doped,mercury vapor lamps.

Preference is given to using gallium-doped and/or iron-doped, especiallyiron-doped, mercury vapor lamps, as described for example in R. StephenDavidson, “Exploring the Science, Technology and Applications of UV andEB Curing”, Sita Technology Ltd., London, 1999, Chapter I, “AnOverview”, page 16, FIG. 10, or Dipl.-Ing. Peter Klamann, “eltoschSystem-Kompetenz, UV-Technik, Leitfaden für Anwender”, page 2, October1998.

Examples of suitable flash lamps are flash lamps from the company VISIT.

The distance of the UV lamps from the applied compositions of theinvention may vary surprisingly widely and can therefore be tailoredvery effectively to the requirements of the case in hand. The distanceis preferably from 2 to 200, more preferably from 5 to 100, withparticular preference from 10 to 50, and in particular from 15 to 30 cm.The lamp arrangement may also be adapted to the circumstances of thesubstrate and the process parameters. In the case of substrates ofcomplex shape, as are envisaged for automobile bodies, those regions notaccessible to direct radiation (shadow regions), such as cavities,folds, and other structural undercuts, may be cured using pointwise,small-area or all-round emitters, in conjunction with an automaticmovement means for the irradiation of cavities or edges.

Irradiation may be carried out under an oxygen-depleted atmosphere.“Oxygen-depleted” means that the oxygen content of the atmosphere isless than the oxygen content of air (20.95% by volume). In principle theatmosphere may also be oxygen-free—that is, made up of an inert gas.Owing to the absence of the inhibitory effect of oxygen, however, thismay cause sharp acceleration of radiation curing, possibly leading toinhomogeneties and stresses in the cured materials of the invention. Itis therefore of advantage not to lower the oxygen content of theatmosphere to zero % by volume.

In the case of the applied dual-curable compositions of the invention,the thermal cure may take place, for example, with the aid of a gaseous,liquid and/or solid, hot medium, such as hot air, heated oil or heatedrollers, or with the aid of microwave radiation, infrared light and/ornear infrared (NIR) light. Heating preferably takes place in aforced-air oven or by irradiation using IR and/or NIR lamps. As in thecase of the actinic radiation cure, the thermal cure may also take placein stages. The thermal cure takes place advantageously at temperaturesfrom room temperature to 200° C.

Both the thermal cure and the actinic radiation cure may be carried outin stages. They may follow one another (sequentially) or besimultaneous. In accordance with the invention, sequential curing is ofadvantage and is therefore used with preference. It is particularlyadvantageous in this case to carry out the thermal cure after theactinic radiation cure.

The actinic radiation cure and/or the thermal cure may be supplementedor supported by the oxidative cure. The oxidative cure may also becarried out alone with a corresponding composition of the curablecompositions of the invention.

The resultant films, moldings, coatings, paint systems, primers,adhesive films, and seals of the invention are outstandingly suitablefor the coating, adhesive bonding, sealing, wrapping, and packaging ofmeans of transport, including aircraft, watercraft, rail vehicles,muscle-powered vehicles and motor vehicles, and parts thereof, theinterior and exterior of buildings and parts thereof, doors, windows,and furniture, and, in the context of industrial coating, of hollowglassware, coils, freight containers, packaging, small industrial parts,such as nuts, bolts or hubcaps, optical components, electricalcomponents, such as wound goods, including coils and stators and rotorsof electric motors, mechanical components, and components for whitegoods, including household appliances, boilers, and radiators.

In particular, however, the compositions of the invention are used ascoating materials for producing coatings, paint systems and primers,preferably for producing primers, in particular for producing primersfor producing multicoat color and/or effect electrically conductive,magnetically shielding or fluorescent paint systems, especiallymulticoat color and/or effect paint systems.

In this utility a further essential advantage of the compositions of theinvention is manifested: namely that they provide coatings, paintsystems and primers whose coat thickness can be varied very widely. Thecoat thicknesses are preferably between 2 and 100 μm.

The resultant primers of the invention are the bottommost coats ofmulticoat paint systems, critically determining the adhesion propertiesand the corrosion prevention. Consequently, deficiencies in the primersare also manifested to a particularly marked extent and can lead todelamination of the primers and/or of the multicoat paint systems and/orto instances of corrosion in the substrates. However, the primers of theinvention have a particularly high adhesive strength both to thesubstrate and to the overlying coats of the multicoat paint systems.Moreover, they protect metal substrates effectively against corrosion.

The substrates of the invention coated with coatings of the invention,bonded with adhesive films of the invention, sealed with seals of theinvention and/or wrapped or packaged with films and/or moldings of theinvention therefore have outstanding long-term service properties and aparticularly long service life.

EXAMPLES Example 1

The Preparation of a Mixture of a Conjuenic Acid Ester (A) and aConjuenic Acid Ester (B)

196 parts by weight of Isomergin acid (Isomerginsature®) SF fromHarburger Fettchemie, containing 60% by weight of an olefinicallyunsaturated C18:2 fatty acid having two conjugated double bonds, weremixed with 100.9 parts by weight of 4-hydroxybutyl acrylate (94 percentpure), 7.0 parts by weight of Novozym® 435 (immobilized lipase fromCandida antarctica from Novozyme, Denmark), 0.05 part by weight ofp-methoxyphenol and 0.01 part by weight of phenothiazine. The resultingreaction mixture was stirred under reduced pressure (5 mbar) at 60° C.for 24 hours. The enzyme was then removed by filtration. This gave 250parts by weight of a pale yellow, slightly oily liquid. This liquid wasable to be supplied without further workup directly for all end uses forwhich it was envisaged.

Analysis gave the following results:

In ¹H nuclear magnetic resonance spectroscopy in CDCl₃ the signal of theester group at 4.18 ppm, deriving from 4-hydroxybutyl acrylate, wasaccompanied by a new signal at 4.08 ppm, which indicated the formationof another ester group. The fatty acid content was determined from thesignal of the methyl group at 0.9 ppm. The signal ratio of ester groupsto fatty acids indicated a degree of esterification of 97%.

Gel permeation chromatography (UV detector, wavelength 254 nm) producedtwo main signals of approximately equal size at a number-averagemolecular weight of 600 daltons and 1 200 daltons. Followingfractionation and analysis by mass spectrometry, these were assigned toIsomergin acid 1-butyl-4-acryloyl ester (A) (X—O—(—CH₂—)₄—O—(O)C—CH═CH₂)and 1,4-butanediol diisomergic acid ester (B) (X—O—(—CH₂—)₄—O—X).

Examples 2a to 2d

The Preparation of a Mixture of a Conjuenic Acid Ester (A) and aConjuenic Acid Ester (B) with Different Lipases

2a) to 2c)

In each case 5 mmol of Isomergin acid SF (1.4 g) were mixed with 5 mmolof 4-hydroxybutyl acrylate (0.721 g) 50 mg of immobilized enzyme and 1mg of 3 angstrom molecule sieve and the mixture was shaken at 40° C. forsix hours. The immobilized enzyme and the molecular sieve were thenremoved by filtration, and the oils obtained were then analyzed by ¹HNMR (degree of esterification) and gel permeation chromatography(product distribution).

Example 2a) was carried out using immobilized lipase from Candidaantarctica (Novozym® 435), Example 2b) using immobilized lipase fromMucor miehei, and Example 2c) using immobilized lipase from Alcaligenessp.

The results of the experiments can be found in Table 1. TABLE 1 Theinfluence of the various lipases on the degree of esterification andproduct distribution Degree of Product distribution: esterificationConjuenic acid ester Example (%) (A) (B) 2a) 96 59 41 2b) 88 96 4 2c) 8594 62d)

1 075.2 g of Edenor® UKG 6010 from Cognis, containing 58 to 63% of anolefinically unsaturated C_(18:2) fatty acid having two conjugateddouble bonds, were mixed with 553.7 g of 4-hydroxybutyl acrylate, 277 mgof 4-methoxyphenol, 55 mg of phenothiazine and 38.4 g of immobilizedlipase from Mucor miehei. The reaction mixture was stirred under reducedpressure (20 to 30 mbar) at 40° C. for eight hours. Ambient air (40liters/hour) was passed in during this time. The enzyme was then removedby filtration. This gave 1 500 g of a pale yellow, oily liquid which wasprocessed further without additional workup.

¹H nuclear magnetic resonance spectroscopy in CDCl₃ gave a degree ofesterification >98% and a product distribution of 93% conjuenic fattyacid ester A and 7% conjuenic fatty acid ester B.

Example 2d) was repeated three times, and the same results wereobtained. This underlines the outstanding reproducibility of the processof the invention.

Examples 3a) to 3c) Preparation of a UV-Curable Coating Material andProduction of Primers (Examples 3a) and 3b)) and of a Multicoat PaintSystem (Example 3c)) from it

The coating material was prepared by mixing 100 parts by weight of3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (Cyracure® UVR6105 from Union Carbide), 0.5 part by weight of a modified silicone(Paint Additive 57 from Dow Coming), 10 parts by weight of3-ethyl-3-hydroxymethyloxetane (Cyracure® UVR 6000 from Union Carbide),20 parts by weight of the mixture of the conjuenic acid esters (A) and(B) from Example 1, 4 parts by weight of triarylsulfoniumhexafluorophosphate (Cyracure® UVR 6990 from Union Carbide) and 1 partby weight of hydroxycyclohexyl phenyl ketone (Irgacure® 184 from CibaSpecialty Chemicals) and homogenizing the resulting mixture.

The coating material had an advantageously low viscosity and was stableon storage. Even after storage for 1 month in the absence of actinicradiation no instances of phase separation could be observed.

The coating material was applied using a rod-type doctor blade to steelpanels of the type HDG (hot-dip galvanized without pretreatment,degreased; Example 3a)) and to steel panels of the type Gardobond 902(alkali metal phosphatized; Example 3b)) from Chemetall. Followingapplication, the coated steel panels were aged at 50° C. for 12 hours.Application was made in a film thickness such that UV curing with a doseof 1 500 mJ/cm2 resulted in a dry film thickness of from 5 to 10 μm(Example 3a) and from 5 to 6 μm (Example 3b).

The resulting primers of Examples 3a) and 3b) exhibited very goodadhesion to the substrate.

In the case of Example 3c) the coating of Example 3b) was overcoatedwith a conventional pigmented top coat material for industrialapplications from BASF Coatings AG. The resultant multicoat paint systemexhibited very good adhesion to the substrate and very good intercoatadhesion.

Examples 4a) and 4b)

Preparation of a UV-Curable Coating Material and Production of Primersfrom it

A coating material was prepared by mixing 56.7 parts by weight of anepoxy polyether diacrylate (Laromer®V 8986 from BASFAktiengesellschaft), 0.8 part by weight of cobalt octoate, 10 percentstrength in white spirit (Octa Solingen Kobalt 6 in D60 from BorchersGmbH), 18.9 parts by weight of the mixture of the conjuenic acid esters(A) and (B) from Example 1, 18.9 parts by weight of 4-hydroxybutylacrylate polyphosphoric acid (diphosphorus pentoxide content 84% byweight) in an 80:20 weight ratio and 4.7 parts by weight ofhydroxycyclohexyl phenyl ketone (Irgacure® 184 from Ciba SpecialtyChemicals) and homogenizing the resulting mixture.

The coating material had an advantageously low viscosity (flow cup, 6 mmnozzle aperture; efflux time 24 s). It was stable on storage: even afterstorage for 1 month in the absence of actinic radiation it wasimpossible to observe any instances of phase separation.

The coating material was applied using a rod-type doctor blade to steelpanels of type HDG (hot-dip galvanized without pretreatment, degreased)from Chemetall. Following application, the coated steel panels were agedat 50° C. for 12 hours. Application was made in a film thickness suchthat curing with UV radiation in a dose of 500 mJ/cm² (Example 4a)) andof 1 500 mJ/cm² (Example 4b)) resulted in a dry film thickness of from 5to 9 μm (Example 4a)) and from 4 to 7 μm (Example 4b)). The resultingprimers exhibited very good adhesion to the substrate.

Examples 5a) to 5c) and Comparative Examples C1a) to C1c)

The Preparation of Coating Materials and Production of Primers from them

The coating materials of Examples 5a) to 5c) and of Comparative ExamplesC1a) to C1c) were prepared by mixing the constituents indicated in Table2 in the stated amounts and homogenizing the resulting mixture. TABLE 2The physical composition of the coating materials of Examples 5a) to 5c)and of Comparative Examples C1a) to C1c) Comparative Examples: examples:Constituent 5a) 5b) 5c) C1a) C1b) C1c) Laromer ® 8986^(a)) 60 60 60 6060 60 Polyphosphoric ester of 4- 20 20 20 20 20 20 hydroxybutylacrylate^(b)) Irgacure ® 184 5 5 5 5 5 5 Isomergin acid SF 4- 20 40 60 —— — hydroxybutyl ester (93 percent pure) 2-ethylhexyl acrylate — — — 2040 60 Cobalt octoate^(c)) — 1 1 — — —^(a))Epoxy polyether diacrylate from BASF Aktiengesellschaft;^(b))Prepared by reacting 80 parts by weight of 4-hydroxybutyl acrylateand 20 parts by weight of polyphosphoric acid with a diphosphoruspentoxide content of 84% by weight;^(c))10 percent strength in white spirit.

The coating materials of Examples 5a) to 5c) and of Comparative ExamplesC1a) were stable on storage in the absence of actinic radiation andshowed no instances of clouding or phase separation even after storagefor one month. They had an advantageously low viscosity and were easy toapply. The coating materials of Comparative Examples C1b) and C1c)exhibited instances of clouding after a short time, which wereattributable to the incompatibility of 2-ethylhexyl acrylate with theother constituents of the coating materials.

The coating materials were applied using rod-type doctor blades to steelpanels of type HDG (hot-dip galvanized without pretreatment, degreased)from Chemetall. Following application, the coated steel panels were agedat 50° C. for 12 hours. Application was made in film thicknesses suchthat curing with UV radiation in a dose of 1 500 mJ/cm² resulted incoatings having dry film thicknesses of from 5 to 9 μm.

UV radiation of the coating materials of Examples 5a) to 5c) was notaccompanied by any odor nuisance. In contrast, irradiation of thecoating material of Comparative Example C1a) was accompanied by anunpleasant odor. In the case of the coating materials of ComparativeExamples C1b) and C1c) an even more intensely pungent odor was produced,leading to a particularly severe odor nuisance. This was attributed toevaporating 2-ethylhexyl acrylate.

The gloss of the coatings was measured in accordance with DIN 67530 atan angle of 60°.

The solvent resistance was determined conventionally by treating thesurface of the coatings with a cotton pad soaked with methyl ethylketone. The measurements were carried out (i) immediately after theproduction of the coatings and (ii) after they had been stored at 50° C.for 15 hours. The parameter reported was the number of double rubs afterwhich damage occurred to the surface.

A measurement was also made of the time after which the coatings swelledwhen kept immersed in methyl ethyl ketone.

The adhesion of the coatings to the substrates was determined by meansof the cross-cut test in accordance with DIN ISO 2409:1994-10.

The corrosion control effect was determined by means of the spray misttest in accordance with DIN 53167:1985-12 on scored coatings. In thistest a check was made after 72 hours as to whether delamination hadoccurred (delamination=D) or not (no delamination=nD). After 100 and 120hours checks were made as to whether marked white corrosion had occurred(white corrosion at the scribe mark >2 mm=W) or minimal or no whitecorrosion (white corrosion at the scribe mark <1 mm=nW).

The results of the experiments can be found in Table 3. TABLE 3 Gloss,solvent resistance, adhesion and corrosion control effect of thecoatings of Examples 5a) to 5c) and of Comparative Examples C1a) to C1c)Methyl ethyl ketone: Cross- Gloss Double rubs Swelling cut Spray misttesting Ex. (60°) (i) (ii) (min) testing 72 h 100 h 120 h 5a)107 >100 >200 >6 GT 0 nD nW nW 5b) 107 25-30 >200 >4 GT 0 D — — 5c) 10515-20 180 3 GT 0 D — — C1a) 107 >100 >200 >6 GT 0 nD nW nW C1b) 83 15-20180 2.25 GT 0 D — — C1c) 34 10-12 80 1.75 GT 1 D — —

Comparison of the results of the experiments indicated that theconjuenic acid ester (A) was a completely valid substitute for theconventional reactive diluent 2-ethylhexyl acrylate. Furthermore, theconjuenic acid ester (A) afforded the essential advantages that duringthe preparation of the coatings in question there was no separation ofthe constituents, no evaporation of monomers and no odor nuisance. Theoutstanding compatibility of the conjuenic acid ester (A) resulted in anoutstanding gloss of the coatings of the inventive examples. Incontrast, at relatively high concentrations of 2-ethylhexyl acrylate,there were instances of clouding and a loss of gloss in the coatings ofthe comparative examples. Moreover, the conjuenic acid ester (A)improved the solvent resistance of the coatings. Not least, it was alsopossible to carry out subsequent air drying of the coatings of Examples5b and 5c.

Example 6 and Comparative Examples C2a) and C2b)

The Preparation of Coating Materials and Production of Primers from them

The coating materials of Example 6 and of Comparative Examples C2a) andC2b) were prepared by mixing the constituents indicated in Table 4 inthe stated amounts and homogenizing the resulting mixture.

The coating materials were applied using rod-type doctor blades todegreased bright steel panels from Chemetall. Following application, thecoated steel panels were aged at 50° C. for twelve hours. Applicationwas made in film thicknesses such that curing with UV radiation in adose of 1 500 mJ/cm² resulted in coatings having dry film thicknesses of8 to 10 μm.

The adhesion of the coatings to the substrates was determined by meansof the cross-cut test in accordance with DIN ISO 2409:1994-10.

The corrosion control effect was determined by means of the spray misttest in accordance with DIN 53167:1985-12 on scored coatings. In thistest a check was made after 72, 120 and 144 hours as to whetherdelamination had occurred (delamination=D) or not (no delamination=nD)and as to whether marked corrosion had occurred (corrosion at the scribemark>2 mm=K) or minimal or no corrosion (corrosion at the scribe mark<1mm=nK).

The results can likewise be found in Table 4. They demonstrate theoutstanding adhesion and very good corrosion control effect of thecoating of Example 6. TABLE 4 The physical composition of the coatingmaterials of Example 6 and of the Comparative Examples C 2a) and C 2b)Examples: Constituents 6 C 2a) C 2b) Phenolic resin (Schenactady SMD31144), 12 — — 35 percent strength solution in Isomergin acid SF4-hydroxybutyl ester (93 percent purity) Phenolic resin (Schenactady SMD31144), — 12 — 35 percent strength solution in 4- hydroxybutyl acrylateAlkyd resin (Alkydal ® R35 from Bayer 30 30 42 AG), 35 percent strengthsolution in isobornyl acrylate N-(2-methacryloyleth-1-yl)ethyleneureaand 10 10 10 isobornyl acrylate in a 1:1 weight ratio Isobornyl acrylate9.4 9.4 9.4 Modified polyisocyanate prepolymer based 17 17 17 ondiphenylmethane diisocyanate (Desmodur ® 2010 from Bayer AG) and 4-hydroxybutyl acrylate Epoxy polyether diacrylate (Laromer ® 8986 18 1818 from BASF Aktiengesellschaft) Cobalt octoate (10 percent in whitespirit) 0.1 0.1 0.1 Irgacure ® 184 5 5 5 Adhesion and corrosion controleffect: Cross-cut test GT 0 GT 0 GT 0 Spray mist test  72 h nK, nD K, DnK, D^(a)) 120 h nK, nD — K, D 144 h K, nD^(b)) — —^(a))Incipient delamination;^(b))Microblisters, 5 mm at the scribe mark.

1. Olefinically unsaturated esters (A) (conjuenic acid esters) of thegeneral formula I:X_(m)Y_(n)   (1), in which the indices m and n stand for 1 or aninteger >1 and the variables X and Y are defined as follows: X is aradical derived from an olefinically unsaturated carboxylic acidcontaining one or more than one carboxyl group, 6 to 60 carbon atoms andat least two conjugated double bonds in the molecule (conjuenic acid);and Y is a monovalent or polyvalent organic radical containing at leastone bond which can be activated with actinic radiation; with theprovisos that (1) m=1 and Y=monovalent radical if X is derived from aconjuenic acid having more than one carboxyl group in the molecule, and(2) n=1 and X=derived from a conjuenic acid having one carboxyl group inthe molecule if Y=polyvalent radical.
 2. Conjuenic acid esters (A) asclaimed in claim 1, further comprising at least one conjuenic acid ester(B) of the general formula II:X_(m)Z   (II), in which the index m stands for 1 or an integer >1 andthe variables X and Z are defined as follows: X is a radical derivedfrom a conjuenic acid; and Z is a hydroxyl-free or hydroxyl-containing,saturated or aromatic organic radical having a valence of ≧1 [or >1]. 3.Conjuenic acid esters (A) as claimed in claim 1, wherein the conjuenicacid is a conjugatedly unsaturated fatty acid (conjuenic fatty acid). 4.Conjuenic acid esters (A) as claimed in claim 3, wherein the conjuenicfatty acids are prepared from olefinically unsaturated fatty acids whoseisolated double bonds have been converted into conjugated double bondsby exposure to alkali or by a biotechnological method.
 5. Conjuenic acidesters (A) as claimed in claim 1, wherein the bonds in the radical Ywhich are activated with actinic radiation are selected from the groupconsisting of carbon-carbon double bonds and of carbon-carbon triplebonds and mixtures thereof.
 6. Conjuenic acid esters (A) as claimed inclaim 5, wherein the bonds in the radical Y which are activated withactinic radiation are carbon-carbon double bonds.
 7. Conjuenic acidesters (A) as claimed in claim 5, wherein the radical Y is selected fromthe monovalent radicals of the general formula III:

in which the variables are defined as follows: R is a bonding electronpair between the olefinic carbon atom and the oxygen atom of theoxycarbonyl group of the conjuenic acid radical or organic radicallinking to the oxycarbonyl group of the conjuenic acid radical; and R¹,R² and R³ independently of one another are each a hydrogen atom ororganic radical, it being possible for at least two of the radicals R,R¹, R², and R³ to be cyclically linked to one another; and from thepolyvalent radicals of the general formula IV:

in which the variables are defined as follows: R⁴, R⁵, R⁶ and R⁷independently of one another are each a bonding electron pair betweenthe olefinic carbon atom and the oxygen atom of the oxycarbonyl group ofthe conjuenic acid radical or organic radical linking to the oxycarbonylgroup of the conjuenic acid radical, with the proviso that a radical R⁴,R⁵, R⁶ or R⁷ which has no linking function is a hydrogen atom or anorganic radical, it being possible for at least two of the organicradicals R⁴, R⁵, R⁶ or R⁷ to be linked cyclically to one another. 8.Conjuenic acid esters (A) as claimed in claim 7, wherein the nonlinkingorganic radicals R¹, R², R³, R⁴, R⁵, R⁶ and R⁷ include at least one ofalkyl, cycloalkyl and aryl groups.
 9. Conjuenic acid esters (A) asclaimed in claim 7, wherein the linking organic radicals R, R⁴, R⁵, R⁶and R⁷ are selected from the group consisting of aliphatic,cycloaliphatic, aromatic, aliphatic-cycloaliphatic, aliphatic-aromatic,cycloaliphatic-aromatic and aliphatic-cycloaliphatic-aromatic radicalswhich m contain at least one of ether, thioether, carboxylate,thiocarboxylate, carbonate, thiocarbonate, phosphate, thiophosphate,phosphonate, thiophosphonate, phosphite, thiophosphite, sulfonate,amide, amine, thioamide, phosphoramide, thiophosphoramide,phosphonamide, thiophosphonamide, sulfonamide, imide, hydrazide,urethane, urea, thiourea, carbonyl, thiocarbonyl, sulfone and sulfoxidegroups.
 10. Conjuenic acid esters (A) as claimed in claim 9, wherein thelinking organic radicals R, R⁴, R⁵, R⁶ and R⁷ contain at least one ofcarboxylate groups-and/of amide groups.
 11. Conjuenic acid esters (A) asclaimed in claim 10, wherein the linking organic radicals R, R⁴, R⁵, R⁶and R⁷ comprise a carboxylate group and of at least one of alkylene,cycloalkylene and arylene groups.
 12. A process for preparing conjuenicacid esters (A) as claimed in claims 1 by reacting (i) at least one ofan olefinically unsaturated carboxylic acid containing one or morecarboxyl groups, 6 to 60 carbon atoms and at least two conjugated doublebonds in the molecule (conjuenic acid) and one ester of said conjuenicacid with (ii) at least one hydroxyl-containing compound containing atleast one bond which can be activated with actinic radiation in thepresence of a catalyst, wherein the catalyst is at least one of anenzyme which catalyzes the transesterification or esterification atleast one organism which catalyzes the transesterification oresterification.
 13. The process as claimed in claim 12, wherein theenzyme is selected from the group of the hydrolases [EC 3.x.x.x]. 14.The process as claimed in claim 13, wherein the hydrolases [EC 3.x.x.x]are selected from the group consisting of esterases [EC 3.1.x.x] andproteases [EC 3.4.x.x].
 15. The process as claimed in claim 14, whereinthe hydrolases are carboxyl ester hydrolases [EC 3.1.1.x].
 16. Theprocess as claimed in claim 15, wherein the hydrolases are lipases. 17.The process as claimed in claim 16, wherein the lipases are obtainedfrom compounds selected from the group consisting of Achromobacter sp.,Aspergillus sp., Burkholderia sp., Candida sp., Mucor sp., Penicilliumsp., Pseudomonas sp., Rhizopus sp., Thermomyces sp. and porcinepancreas.
 18. The process as claimed in claim 12, wherein the organismsare selected from the group consisting of naturally occurringmicroorganisms, genetically modified microorganisms, single-celled lifeforms of and cells which comprise at least one enzyme which catalyzesthe transesterification or esterification.
 19. The process as claimed inclaim 18, wherein the organisms are selected from the group consistingof Achromobacter sp., Aspergillus sp., Burkholderia sp., Candida sp.,Mucor sp., Penicillium sp., Pseudomonas sp., Rhizopus sp., Thermomycessp. and cells from porcine pancreas.
 20. The process as claimed in claim12, wherein the hydroxyl-containing compounds (ii) are selected from thegroup consisting of carboxylates and carboxamides of the general formulaV to X

in which the variables R, R¹, R², R³, R⁴, R⁵, R⁶ and R⁷ are as definedabove and the variable Q stands for an atom or group selected from thegroup consisting of an oxygen atom, a primary imino group and asecondary imino group, and the variable R⁸ stands for ahydroxyl-containing monovalent organic radical.
 21. The process asclaimed in claim 20, wherein the monovalent organic radical R⁸ includesor consists of at least one radical selected from the group consistingof hydroxyl-containing alkyl, cycloalkyl and aryl radicals.
 22. Theprocess as claimed in claim 21, wherein the hydroxyl-containing alkylradical R⁸ is at least one of a hydroxyethyl radical, 2-hydroxyproplyradical, 3-hydroxypropyl radical and 4-hydroxybutyl radical.
 23. Theprocess as claimed in any of claims 20, wherein the hydroxyl-containingcompound (ii) is selected from the group consisting ofhydroxyl-containing esters of and hydroxyl-containing amides of at leastone of acrylic acid, methacrylic acid, ethacrylic acid, crotonic acid,cinnamic acid, cyclohexene carboxylic acid,endomethylenecyclohexanecarboxylic acid, norbornenecarboxylic acid,dicyclopentadienecarboxylic acid, fumaric acid, maleic acid, itaconicacid, endomethylenetetrahydrophthalic acid andmethylendomethylenetetrahydrophthalic acid, maleic acid, fumaric acidand itaconic acid.
 24. The process as claimed in claim 22, wherein thehydroxyl-containing compound (ii) is 4-hydroxybutyl acrylate.
 25. Theprocess as claimed in claims 21, wherein at least one of the waterresulting during the reaction and the hydroxyl-containing compoundsresulting during the reaction are removed from the reaction mixture asit or they are formed or immediately after they have been formed. 26.Compositions comprising acid esters (A) as claimed in claim 1 whereinsaid compositions are curable with at least one of actinic radiation,thermally and oxidatively.
 27. Materials selected from the groupconsisting of coating materials, adhesives, sealants to producecoatings, paint systems, primers, adhesive films, seals, moldings, andself-supporting films comprising the compositions of claim 26.